Water Research ( IF 12.8 ) Pub Date : 2020-03-14 , DOI: 10.1016/j.watres.2020.115705 Junjie Qiu , Fan Lü , Hua Zhang , Yulong Huang , Liming Shao , Pinjing He
Biological treatment of wastewater always leaves plenty of refractory dissolved organic matters (DOM) in effluents, specifically for fresh waste leachate. Aiming at comprehending the production and removal of these compounds, this study investigated DOM transformation in a simultaneous denitrification and methanogenesis with activated sludge (SDM-AS) system with backflow for raw fresh leachate. Chemical oxygen demand (COD) was reduced to 854 ± 120 mg/L from 63000 ± 470 mg/L, and total nitrogen (TN) decreased from 2500 ± 647 mg/L to 404 ± 75 mg/L, during an operation of 440 days. The SDM reactor was fed at organic loading rate of 6.70 kgCOD/(m3·d) to generate 2.52 L CH4/(L·d). Molecular information of leachate DOM was acquired by using ultra-performance liquid chromatography coupled with Orbitrap mass spectrometry. A DOM classification based on Venn diagram was proposed to divide leachate DOM into seven categories. It revealed that 76–84% of final effluent DOM stemmed from biological derivation. Posteriori non-target screening showed anthropogenic micropollutants, e.g. phosphate flame retardants and industrial agents, probably contributed to the remnant native inert DOM in the effluent at the levels of 5–200 μg/L. DOM Classification also showed a portion of bio-derived DOM can be completely removed by SDM-AS processes, while the rest bio-derived DOM can be partially removed depending on DOM nature and the recirculation ratio. The removal and production rate of specific bio-derived DOM in respective SDM and AS units theoretically satisfied a hyperbolical and dual relationship in terms of mass balance. The persistence of each DOM category was sorted. These results showed anaerobic degradation could be a promising approach to reduce aerobic bio-derived DOM.
中文翻译:
新鲜垃圾渗滤液同时反硝化和甲烷生成过程中持久存在的天然和生物来源的溶解有机物分子
废水的生物处理通常会在废水中留下大量难熔的溶解有机物(DOM),特别是对于新鲜的垃圾渗滤液。为了理解这些化合物的产生和去除,本研究研究了利用活性污泥(SDM-AS)系统同时进行反硝化和甲烷生成过程中的DOM转化。未加工的新鲜渗滤液回流。在440次运行中,化学需氧量(COD)从63000±470 mg / L降至854±120 mg / L,总氮(TN)从2500±647 mg / L降至404±75 mg / L天。将SDM反应器以6.70 kgCOD /(m 3 ·d)的有机负荷进料,以生成2.52 L CH 4/(L·d)。渗滤液DOM的分子信息通过使用超高效液相色谱与Orbitrap质谱联用获得。提出了一种基于维恩图的DOM分类法,将渗滤液DOM分为七个类别。结果表明,最终出水的DOM中有76–84%来自生物衍生。后验非目标筛选显示,人为的微量污染物,例如磷酸盐阻燃剂和工业试剂,可能以5-200μg/ L的水平造成了废水中残留的天然惰性DOM。DOM分类还显示,可以通过SDM-AS工艺完全去除一部分生物来源的DOM,而其余的生物来源的DOM则可以根据DOM的性质和再循环率部分去除。在质量平衡方面,在相应的SDM和AS单元中特定生物来源的DOM的去除率和生产率在理论上满足了双曲线和对偶关系。对每个DOM类别的持久性进行了排序。这些结果表明,厌氧降解可能是减少有氧生物来源的DOM的有前途的方法。